It is an integrated complex of structures that combined architectural elements and styles from Persian, Turkish, Indian and Islamic styles. It is not clear as to who designed the Taj Mahal, although as per ICOMOS report Ustad Ahmad Lahauri is generally considered as the principal designer of Taj Mahal. . Elevation, superstructure, balanced and symmetrical combination of its parts gives Taj Mahal a wonderful artistic and visual effect. Therefore, it is seen more as a work of beauty than a mere Mughal mausoleum. UNESCO declared it as a heritage site in 1983.
Mumtaz Mahal, the wife of Shah Jahan died in 1631. The story goes that Mumtaz Mahal extracted four promises from the emperor while she was alive, firstly, he will build the Taj a mosulem in her memory, secondly he should marry again, thirdly, he will be kind to their children, and fourthly, he would visit the tomb on her death anniversary. Shah Jahan chose to construct the monument on the banks of the Yamuna River on the southern edge of Agra on a piece of land purchased from Raja Jai Singh. Lot of efforts went into stabilise the sands on the river bank. Construction of the tomb began in 1631 and was completed in 1653 as inscribed by the calligrapher Amanat Khan on the north arch of the gate which says "Finished with His help, the Most High". 
The construction had employed twenty thousand people and the material was brought in from all over India and central Asia. The building had walls of brick which are few meters thick and rubble inner cores faced with either marble or sandstone locked together with iron dowels and clamps. Building materials were transported using elephants and marble was brought from Makrana in Rajasthan. The construction of the building had cost 5,000,000 Rupees. The emperor ensured that the monument became a place for seeking eternal peace with arrangements for continuous recitation of Quran and the prayers to the god.
The complete complex of the Taj Mahal extends over an area of 561.2 m X 300.84 m and comprises of five main elements: the main gateway named Darwaza, the Bageecha or garden, the mosque, the rest house (Naqqar Khana), and the Rauza or the Taj Mahal mausoleum. The actual Tomb of Mumtaz is situated inside the Taj. One can see harmonization of elements & styles of Persian, Central Asian, and Islamic architecture in the Taj architecture.
Black and white chessboard like marble floor, the four tall minarets at the corners and the majestic grand dome in the middle all combine together to give a visual treat. The carvings, calligraphy and density have been so arranged to give an optical illusion of fineness.
The focus of Taj Mahal is the white marble tomb, which stands on a square plinth of 56.m across and has a height of 67.97 m excluding the podium. The square plinth has been champered at corners to give an octagonal shape. Four octogonal halls surround the octogonal main tomb with each having domes of proportionate size. The mausoleum is faced in white marble; with pietra dura ornamentation.Interior is adorned with Koran inscriptions.
The garden in front with dimensions of 296.31 m x 296.31 m has been so arranged that the symmetry can be seen everywhere. The mosque with 4 Octagonal towers and 3...